Rim flow swimming pools are old. For instance, the outdoor swimming pool at Glenwood Springs, Colo., the water to which is derived from natural springs from which the water issues at a temperature of above 100.degree. F, is a rim flow swimming pool which has been in existence for half a century or more. In this pool, the overflow of water from the pool takes place over the rim and is drained through openings in slabs spaced apart along the drain gutter, which is spaced from the edge of the pool. These drain slabs are relatively thick and heavy and are removable for access to the drain at spaced intervals, for cleaning purposes.
Other rim flow swimming pools are disclosed in prior U.S. patents. For instance, Booraem et al U.S. Pat. No. 1,797,397 of 1931 shows a rim flow swimming pool in which the rim has an upstanding nose at the edge of the pool. Both a portion of the upper edge of the pool and the inner wall and bottom of the gutter, for removing water drained from the pool, are formed by a relatively hevy casting, while a second heavy casting forms the outer wall of the gutter and an upstanding barrier, together with a second drain gutter further outwardly from the edge of the pool. Castings with slots cover each of the drain gutters. Variations of this construction are also shown by Booraem et al, although each involves relatively heavy castings.
Kennedy, U.S. Pat. No. 2,982,970 of 1961 shows a swimming pool edge structure in which a drain gutter is formed in the concrete which surrounds the pool, and a cast grate bridges this drain gutter, the cast grate having an inner nose and a series of slots, for drainage of water into the gutter beneath, but the nose is supported by spaced, depending elements between which water also drains from the pool.
Whitten, Jr., U.S. Pat. No. 3,386,107 of 1968 shows a rim flow swimming pool in which a rectangular, tubular member forms the edge of the pool, being placed above the wall of the pool around the edge thereof, with an angle section forming the bottom and outer wall of the drain gutter and also extending upwardly to a deck which surrounds the pool and having an outer depending flange embedded in the concrete of the deck. A slotted grating, formed in sections, is placed on top of the gutter.
Costello, U.S. Pat. No. 3,585,656 of 1971 shows a swimming pool coping construction comprising a relatively heavy grating cast from concrete or the like, and provided with reinforcement interspaced with slots in the grating. This grating is provided with an upstanding nose at the inner edge and is placed over a drain gutter formed in the concrete of which the walls of the pool are formed.